Tardigrades

These microscopic eight-legged “bears of the moss” were once candidates to be the main model organism for studies of development. Since displaced from that role by C. elegans, they remain marvels of the invertebrate world and are establishing a place as a model organism for teaching. These rugged creatures can survive temperatures ranging from –273 degrees Celsius to +150 degrees Celsius, pressures between pure vacuum and 6,000 atmospheres, noxious gases, and x-ray and ultraviolet radiation. The author’s student intern discovered a California specimen that turned out to represent a new genus of Tardagrada.